A cam follower of the pre-cited type, configured here as a roller tappet, is disclosed in DE 102 10 747 A1 that is considered generic. The lash of the two pistons in their receptions that is required for coupling causes them to tilt in the receptions. This occurs during every cam lift and causes an underside of the pistons to abut against a corresponding counter surface of the annular reception of the outer element. Due to the tilting of the pistons, a contact zone is shifted from the inside of the counter surface of the annular groove (radially outside) to an edge section of this at the parting plane between the elements (radially inside). Thus, in this case, only a two-point contact exists.
This two-point contact in the edge section leads to an extreme rise of the contact forces. If, at the same time, shape, rectangularity and parallelism variations exist, the aforesaid effect is intensified. Due to the high loads precisely in the edge region, an undesired increase of lash in the coupling region takes place over the service life of the cam follower. The edge region gets deformed. In the worst case, this can lead to a jamming of the two elements or to a failure of the coupling function.